So what do you make of today's line-ups folks? It's all experimental of course, with a month and a bit until the World Cup starts.

Whether you're an Ireland, Scotland, England or France supporter, let us know who you think could be the surprise name to sneak into your side's XV at the World Cup.

Use #bbcrugby on Twitter to give us your penny's (or cent's) worth.

And how are those nerves holding up Sean O'Brien? It's not every day you get to captain your country. But the sight of his emerald green jersey hanging up at the Aviva Stadium may well get the hairs standing up.

Great to see a couple of names in the Scotland line-up. Ruaridh Jackson, who is more familiar at 10 than full-back, is back in the fold after a horrible knee injury. And lock Grant Gilchrist puts his arm injury problems behind him to start.

Image source, Getty Images

New Zealand-born flanker Hugh Blake makes his long awaited debut for Scotland, after a bit of a furore over whether he should be anywhere the squad. In fact, none of Scotland's back row were born in Scotland.

Starters: Ruaridh Jackson; Sean Lamont, Richie Vernon, Peter Horne, Tim Visser; Greig Tonks, Henry Pyrgos (captain); Ryan Grant, Fraser Brown, Jon Welsh, Jim Hamilton, Grant Gilchrist, Blair Cowan, Hugh Blake, David Denton.

Replacements: Ross Ford, Gordon Reid, Mike Cusack, Rob Harley, John Barclay, Sam Hidalgo-Clyne, Duncan Weir, Matt Scott.

Image source, Getty Images

Sean O'Brien, the Leinster eight, becomes the 104th man to captain Ireland today. His provincial team-mate Jack Conan - who I will be re-christening Conan the Barbarian - wins his first senior cap.

Starters: Simon Zebo; Tommy Bowe, Jared Payne, Gordon D'Arcy, Luke Fitzgerald; Ian Madigan, Isaac Boss; Dave Kilcoyne, Sean Cronin, Mike Ross, Devin Toner, Dan Tuohy, Jack Conan, Chris Henry, Sean O'Brien.

Replacements: Richardt Strauss, Michael Bent, Nathan White, Paul O'Connell, Jordi Murphy, Eoin Reddan, Paddy Jackson, Dave Kearney.

Ireland got their World Cup warm-up campaign under way last weekend, beating Wales 35-21. Joe Schmidt's side are heavily changed to face Scotland, who are having their first outing of the summer and are looking for a first win of 2015.

Let's have a look at the line-ups...

Image source, AFP

It's the summer. The rugby is on.

It's a very simple formula, but by my calculations that means people up and down the country have their rugby shirts on.

Take a photo of you, your baby, your dog or your grandma showing their colours. We'll use a few of them right here.

Use #bbcrugby on Twitter to get involved.

"Here comes the summer's son. He burns my skin."

Famous words sung by Texas.

I can only assume the "son" Charlene Spiteri refers to was a premonition of the sizzling heat and burning excitement that accompanies the build-up to a World Cup.

No doubt Scotland's favourite mid-90s, inoffensive rocker will be watching her country take on the Irish today (17:00 KO).

Will she stay in her sofa for England v France (20:00 KO)? I blooming well hope so. I hope you do too.